CODEWITHSUNDEEP
processlinux-kernel
user609306
user609306

Reputation: 1371

process control block vs process descriptor

what is the exact difference between process control block and process descriptor?.

I was reading about kernel of linux. It was written that there is some thread_info structure which contains the pointer to actual process descriptor table. It was written that the thread_info lies just above/below of kernel stack. So definitely thread_info is in main memory. But what about actual process descriptor task_struct? where is it located? If process descriptor resides in main memory, where is the actual place for it ?

Upvotes: 0

Views: 4044

Answers (2)

bruno
bruno

Reputation: 11

In the kernel, the process descriptor is a structure called task_struct, which keeps track of process attributes and information. All kernel information regarding a process is found there.

Upvotes: 1

Karmastan
Karmastan

Reputation: 5706

The thread_info and task_struct structures are just two different structures that hold different pieces of information about a thread, with the thread_info holding more architecture-specific data than the task_struct. It makes more sense to split up the information rather than keep it all in the same structure. (Although you could put them in the same struct; the 2.4 Linux kernel did this.)

How those structs are allocated depends on the architecture you're using. The relevant functions you want to examine are alloc_task_struct() and alloc_thread_info().

Upvotes: 3

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